Turbine and turbine nozzle construction



0 T. M. RYAN ETAL 2,526,281

' TURBINE AND TURBINE NOZZLE cons'muc'rxon Filed April 10, 1947 2Sheets-Sheet 1 Oct. 17, 1950 -r. M. RYAN EVI'AL I TURBINE AND TURBINENOZZLE consmuc'rxou 2 sheets-sheet 2 Filed April 10, 1947 reams a.11,1950

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E AND ruannaanozzrn Thomas Paramus,- and Walter J. Bomloin, Nutiey, N.1.. assignors to. Wright Aero-,.

nautical Corporation, a corporation of New York Application April 10,1947, Serial No. 740.702

f scum. (crass-s) This inventidn relates to fluiden'gines and is moreparticularly directed to an annular nozzle construction for the enginemotive fluid.

In a gas turbine power plant having a plurality of independentlyoperable gas generators, the general practice is to circumferentiallydivide the turbine nozzle into segments. one for each gas generator. Forexample. with two gas generators. each generator would supply turbinemotive fluid approximately to only 180' of the annular turbine nozzlewhereby, with one of the gas generators shut down, the turbine bladeswould receive motive fluid from only $6 the circumference of the nozzle.

This conventional arrangement has numerous drawbacks. particularlyduring partial admission of the turbine motive fluid, that is. when lessthan all of the gas generators are operating. For example, with partialadmission of turbine motive fluid; there is bufleting of the turbineblades by the turbine motive fluid; the intermittent fllling andemptying of the spaces .between the turbine blades by said fluid resultsin pressure surging; the temperature distribution around the nozzle isnon-symmetrical relative to the nozzle axis whereby the turbine bladesalternately rotate through hot and cold zones; and the pressure of saidmotive'fluid on the turbine rotor is nonuniform around the rotor.

An object of this invention comprises the pro- Q Vision of a novelturbine nozzle construction in which the aforementioned disadvantages.which accompany partial admission of turbine motive fluid, are avoided.Specifically the invention comprises a turbine nozzle construction andturbine therefor. in which the turbine nozzle structure comprises aplurality of concentric nozzles each directing turbine motive fluid froman individual combustion chamber or gas generator against the turbineblades. Said nozzles are concentrically disposed about each other andthe turbine blades extend radially across the concentric discharge endsoi said nozzles. In addition each turbine blade is divided into aplurality of radially-spaced sections each receiving turbine motivefluid from only one of said nozzles.

Other objects or the invention will become apparent upon reading theannexed detailed description in connection with the drawing in which:

Figure l is a schematic view partly in section of a gas turbine powerplant embodying the invention.

Figures 2, 3, 4, 5, and 6 are sectional views taken along lines 2-2,8-3, H, 5-8, H respectively of Figure l; and

a z Figure '7 is a perspective view of the discharge end of thecombustion chambers.

Referring to the drawing. reference numerals i0 and i2 designate ductsfor conveying a fluid under pressure. Each duct i0 and i2 may compriseall or part of a combustion chamber to which air under pressure issupplied and mixed with fuel for combustion therein. or each said ductmay simply comprise a passage for conveying fluid under pressure fromeither a combustion chamber or some other source of fluid underpressure. as for example, the exhaust from a highpressure turbine. Thefluid ducts iii and I2 supply combustion gases or other suitable fluidunder pressure to a turbine nozzle construction from which said fluid isdirected against the blades ll of the turbine rotor It for driving saidrotor.

The cross-section of the fluid duct it gradually changes from a tubularor circular cross-section,

at a relatively upstream point. through the crosssections' indicated atMa and liib in Figures 4.

and 5 respectively, to an annular discharge end iilc as best illustratedby the progressive sectional 'views of Figures 3, 4. 5, and 6 and by theperspective view of Figure '7. The cross-section of the fluid duct i2goes through a similar transition from a circular or tubularcross-section, through its cross-sections indicated at Ho and lib to itsannular discharge end I20. In order to permit the annular nozzles ordischarge ends I00 and I2c of the fluid ducts to be concentricallydisposed one about the other, the outer diameter of the annulardischarge end He of the fluid duct i2 is slightly smaller than the innerdiameter of the annular discharge for lilc of the fluid duct 10. Inaddition the tubular portions of the ducts I0 and I! are disposed onopposite sides 01' and are spaced from the common axis of their annu-.,

lar discharge ends.

The discharge ends of the fluid ducts l0 and I2 merge with a fixedannular nozzle vane section it having vanes 20 comprising sectons 20aand 20b for directing the combustion gases. or other, motive fluidagainst the turbine rotor blades It. The nozzle vane sections Ilia-and20b are generally similar and are separated by an annular flange 22which is disposed in alignment with the small annular gap between theconcentric discharge ends iilc and P20 of the fluid ducts i0 and I2. Thearrangement is such that the annularflange 22 in effect joins the facingannular walls of the discharge ends Hlc and He. For structural reasons.the nozzle vane section it is not rigidly secured to the discharge endsof the fluid ducts l0 and I! but instead these parts are disposed intelescopic labyrinthseals 2,4, 28, and II therebetween,

with the aforedescribedconstruction the mo- "as... -wun I tail in itspresent preferred embodiment, it will be obvious to those skilled in theart, aiter untive sum supplied through the fluid duct no dis-.

charges through the annular nozzle provided by the nozzle vane section aand themotive fluid supplied through the fluid duct l2 dischargesthrough the annular nozzle provided bythe nozzle vane section 201:. u

The-turbine rotor I8 is mounted for rotation on the axis of the annulardischarge ends loo and l2c and a shaft extension 28 of the rotor i8extends co-axially through said annular discharge ends. 'As illustratedthe rotor I6 is provided with spaced sets or stages of turbine blades asis conventional practice in multi-stage turbine rotors. Each turbineblade' I is divided into two sections Ila and Nb separated by an annularflange or shelf construction projecting laterally on opposite sides 01'each turbine blade into abutting engagement with the correspondingflanges 30 of adjacent blades. If desired said flanges 30 may be weldedor otherwise secured together along their abutting edges to form anintegral rim separating the blade sections a. and Nb. Whether or not theflanges 30 are welded together these flanges 30 greatly strengthen theblades H.

The turbine blade flanges III are disposed in alignment with the annularnozzle flange 22 whereby the turbine motive fluid directed by the nozzlevanes 20a discharges against only the blade sections I la and'theturbine motive fluid directed by the nozzle vanes 20b discharges againstonly the blade sections Mb. From the discharge end of the turbine rotorblades H the turbine motive fluid exhausts into an exhaust duct 32.

With the atoredescribed construction when turbine motive fluid is beingsupplied through both fluid ducts Ill. and I2, there is iul admission ofturbine motive fluid to both turbine blade sections a and Ill). 'Ihatis, motive fluid is admitted to both said blade sections from the entire360 01' their nozzles 20a and 201). With onhr one of the fluid ducts IIIor 12 supplying motive fluid, there is full admission of turbine motivefluid from the-entire 360 of its nozzle 20a or 20b to the associatedturbine blade sections Ha or [4b thereby maintaining the operatingefllciency of this section of'the turbine blades. In addition theclearance between the annular flange 22 and the composite annular bladeflange 30 may be made quite small thereby minimizing leakage of turbinemotive fluid from one of the nozzles 20a or 20b to the other duringpartial admission. Alsowith the present invention,

, there is no blade buil'eting and/ or pressure surging during partialadmission of the turbine motive fluid as occurs in the conventionalarrangement wherein certain circumierentially spaced sections of anannular name are'blanked out during partial admission. Furthermore, withthe present invention the temperature and pressure conditions around thenozzle and/or turbine rotor are substantially symmetrical relative tothe rotor axis.

The invention has been described in connection with a gas turbine powerplant provided with two combustion chambers. Obviously, however, theinvention is appiicable to a gas turbine power plant having any pluralnumber of combustion chambers.

- deratanding our invention, that various changes and modifications maybe made therein without departing from the spirit or scope thereof. Weaim in the appended claims to cover all such modifications.

We claimas our' invention:

1. A pair 0! ducts tor the motive fluid of an engine; said ducts havingconcentric annular passage portions disposed one within the otherthroughout parts 01' their respective lengths, throughout other parts oftheir respective lengths said ducts each having a tubular passageportion in series with its annular passage portion, each duct a.sohaving an intermediate passage portion providing a smooth transitionbetween its said annular and tubular passage portions,

/each 0! said duct passage portions extending passage portions disposedone within the other substantially parallel to the axis of said annular.passage portions with the tubular passage portion of one duct beingdisposed laterally to one side of the tubular passage portion oi theother duct.

2. A pair of ducts for the motive fluid of an engine; said ducts havingconcentric annular throughout parts of their respective lengths,throughout other parts of their respective lengths said ducts eachhaving a tubular passage portion in series with its annular passageportion, said tubu.ar passage portion of one duct being dis posed to oneside of the axis of said annular passage portions and said tubularpassage portion of the other duct being disposed on the diametricallyopposite side of said axis.

3. In a turbine power plant; a pair of ducts for supplying motive fluidto the turbine rotor, said ducts having annular discharge passageportions disposed one within and immediately adjacent to the other, eachsaid duct also having a tubular passage portion and an intermediatepassage portion serially connecting and providing a smooth transitionbetween its annular and tubular passage portions, each of said ductpassage portions extending substantially parallel to the axis of saidannular passage portions with the .tubular passage portions of saidducts being disposed on diametrically opposite sides of said axis; andblades on said rotor adapted to receive motive fluid from the annulardischarge passage portions of said ducts for imparting rotation to saidrotor, each of said turbine blades having a laterally extending flangeintermediate its ends such that said flanges define an annular rimseparating each blade into two sections, the one blade section of eachblade being disposed in alinement with one of said annular dischargepassages and its other blade section being disposed in alinement withthe other of said annular discharge passages.

THOMAS M. RYAN. WALTER. J. ROMLEIN.

REFERENCES CITED The following references are of record in the file ofthis patent: 1

UNITED STATES PATENTS Number Name Date 750,316 Stumpf Jan. 26, 19041,328,835 Kasley Jan. 27, 1920 2,438,357 Bloomberg Mar. 23, 1948

